package twentytwenty;

import java.util.Deque;
import java.util.LinkedList;

/**
 * @Author: Spider Man
 * @Description: 20.有效的括号
 * @Date Created in 2020-09-21 11:59
 * @Modified By:
 */
public class IsValid_20 {
    public static void main(String[] args) {
        String s = "){";
        System.out.println(isValid(s));
    }

    public static boolean isValid(String s) {
        if (s.length()==0 || s.length() == 1){
            return false;
        }
        char first = '(';
        char second = '[';
        char third = '{';
        char first1 = ')';
        char second1 = ']';
        char third1 = '}';
        Deque<Character> linkedList = new LinkedList<>();
        int len = s.length();
        for (int i = 0; i < len; i++) {
            if (s.charAt(i) == first){
                linkedList.add(first);
            }else if (s.charAt(i) == second){
                linkedList.add(second);
            }else if (s.charAt(i) == third){
                linkedList.add(third);
            }else if (s.charAt(i) == first1 && linkedList.size() != 0 && linkedList.getLast() == first){
                linkedList.removeLast();
            }else if (s.charAt(i) == second1 && linkedList.size() != 0 &&  linkedList.getLast() == second){
                linkedList.removeLast();
            }else if (s.charAt(i) == third1 && linkedList.size() != 0 && linkedList.getLast() == third){
                linkedList.removeLast();
            }else if (s.charAt(i) == first1 && (linkedList.size() == 0 || linkedList.getLast() == second || linkedList.getLast() == third)){
                return false;
            }else if (s.charAt(i) == second1 && (linkedList.size() == 0 || linkedList.getLast() == first || linkedList.getLast() == third)){
                return false;
            }else if (s.charAt(i) == third1 && (linkedList.size() == 0 || linkedList.getLast() == first || linkedList.getLast() == second)){
                return false;
            }
        }
        return linkedList.size() == 0;
    }
}
